Hot Rods Power pac

I’m having my 283 built. Pretty sure it has power pack heads heads. Needs bored for sure. Going to be 4 speed behind it,302 intake or 62 vette intake. Not sure on difference,have a set of 461and 462 heads and the power pac heads. Which one would work best? Wanting just a small cam also , Not racing just a little thump. Also anybody have info on these rotors? Thanks

 

Power Pack heads have the triangle on the end. The valves and ports are smaller than the "double hump" 461 or 462 heads. PP heads work great up to about 5000 rpm, the bigger heads work better at higher rpm.

I have the original PP heads on the 250 hp 327 in my 62 Vette, with the "small" intake and "small" WCFB carb, with a mild cam. It has the same torque as the higher performance engines, and pulls great up to about 5000 rpm. It would make more power if I put bigger heads, intake, carb, and cam in it...but it turns out that driving it around how it is is plenty fun, and it gets decent gas mileage, too.

So, think about what you want out of the car. If you want to get that extra 100 hp from using that extra 2000 rpm from 5000-7000, then you want a bigger cam, bigger heads, and bigger intake. If not, then keep it small.

also, having more cubic inches really helps the torque, and you'll be missing out on that with the 283 vs going to a 327 or something.

 

All I can say is those are the strangest looking heads I've ever seen.

 

How much is the 283 being bored?

 

If I had all three pairs of heads I'd always choose to go with either of the camel hump heads. But be sure those heads with larger valves clear the cylinder walls on a 283 bore! I know the 1.94"/1.60" valves will, but not sure the 2.02" valves will.

 

Thanks.

 

I would put the 1.94" valve head not any 2.02". You will be much happier with them.

Pat

 

If you're having the power pack heads redone anyway, a good compromise would be to replace the stock 1.72 inch intake valves with 1.84 inch valves from a 305 H.O. engine.

 

The 2.02 valves are too large in the 283 bore and will hit the cylinder unless you bore it way out, which has its own risks.

The Power Paks with 1.84 valves is what I'm planning on for my 283 for a nice responsive street build.

 

Are these power pack with heads

 

??

 

yes

 

Ok. I was reading you can’t run 461 heads on a 283. Is that correct?

 

They work with the 1.94 intake valve version, the 2.02's require the eyebrow in the bore.

 

‘461’s got the 2.02 valves in 1964 for the 365 and 375 horse 327’s and those valves need a 4 inch bore so there’s no interference. Keep in mind earlier ‘461 castings could have been updated with 2.02’s.

 

I'm thinking PP heads were about 57cc combustion chamber volume. After 59 or 60 the "diamond" casting mark had larger combustion volume so a compression loss for a 283. I had occasion to install an L79 cam in a legit '57 Chevy with power pack engine with a C AFB on the stock manifold using an adapter. It ran great until I pulled a rocker arm stud.

 

This, but make sure the machine shop actually opens the throats up too or the whole operation is pointless. There are a few unscrupulous eBay sellers that list 305 heads with “big valves” and no additional work done.